Method and device for determining the body weight of a person

ABSTRACT

This version will replace all prior versions in the application: 
     A method and a device for determining the body weight of a person, in which at least one parameter typical for a biological impedance measurement is determined and transmitted to an evaluation unit. The evaluation unit processes the measurement value together with individual or several individual data of the person as well as taking into consideration statistical data concerning other persons, in order to determine an estimated value for the weight of the person.

The invention relates to a method for measuring the body weight of a person, wherein by means of measuring technology at least one parameter typical for a biological impedance measurement is determined and is transmitted to an evaluation unit.

Moreover, the invention relates to a device for determining the body weight of a person, wherein the device includes at least one sensor for determining at least one parameter typical for a biological impedance measurement, and wherein the sensor is coupled to an evaluation unit.

In a predominant number of persons, the weight measurement can be carried out in a simple manner by having these persons stand on a scale and the corresponding body weight is indicated. The weight measurement has been found problematic in bedridden patients and/or patients who require aid. However, it is particularly with these persons that the determination of the body weight is of special significance in order to be able to draw conclusions concerning the nutritional state. Frequently in the case of such persons, there is the problem that these persons become overnourished or undernourished, which leads to undesirable weight gains or losses. Similarly, there may be the problem that lack of movement and stimulation lead to a loss of muscle.

In order to measure the body weight of such persons, it is frequently necessary to lift and/or move the patients out of the bed. Inasmuch as possible, the persons are then placed on a scale or are weighed in a sitting position. Even more complicated is the determination of the body weight by weighing the bed together with the patient and then correspondingly determine the weight of only the bed. Such a sequence is also subject to significant difficulties since especially in persons requiring aid the beds are frequently not easily accessible from all sides. Moreover, the patients are frequently connected to measuring or medical supply devices whose own weight also has to be taken into consideration.

Accordingly, the previous work sequences in the determination of the body weight of bedridden patients may be labor intensive, imprecise, and for the patient at least unpleasant and frequently even painful.

Therefore, it is the object of the present invention to improve a method of the type mentioned in the introduction in such a way that the weight determination is reinforced in lying or sitting patients.

In accordance with the invention, this object is met in that the evaluation unit processes the measurement value together with individual and several additional individual data of the person and, taking into consideration statistical data concerning other persons determines an estimated value for the weight of the person which is as accurate as possible.

Another object of the present invention is to construct a device of the type mentioned in the introduction in such a way that the determination of the weight of lying persons is supported.

In accordance with the invention, this object is met in that the evaluation unit includes an individual storage unit for individual data of the person as well as a reference storage unit for statistical data of other persons, and that, for interconnecting the measuring parameters, the evaluation unit is constructed with contents of the individual storage unit as well as with contents of the reference storage unit.

The method according to the invention and the device make it possible to determine the nutritional state of a patient without knowing the exact actual weight of the patient. Consequently, it is particularly possible to represent gains or losses in the body weight. This can take place with or without a serial measurement. In particular, it is possible to determine the weight of the patient without having to move the patient.

A determination of the measurement value can be effected preferably with the use of a so-called Body Composition Analyzer (BCA). For example, such a device is capable of determining the weight proportions of muscles, fat, water and bones within the human body. In this regard, typically further characterizing values of the respective person are taken into consideration as influencing parameters, for example, the age, the gender, as well as the ethnicity. The weight of the respective person is usually determined by a weighing process. Accordingly, in the case of a conventional use of such a BCA device, the weight of the person is taken into consideration as an influencing parameter of an evaluation algorithm. Actual measurement values of the BCA device are impedance values of the body between predetermined measuring points. The measuring points are typically found in the areas of the hands or the feet of the respective person.

In accordance with the invention, the functional dependency of the values of the parameters determined by the BCA device on the weight of the person is utilized, mathematically speaking, for determining this weight through a resolution of the respective functional dependency according to the weight. The accuracy of the determination of the weight can be improved by additionally considering statistical data of comparison persons.

An increased accuracy in the determination of the estimated values for the weight of the person can be achieved in that the evaluation unit takes into consideration at least one additional measuring value which is in the past with respect to time.

In particular, it is being considered to carry out a serial measurement.

In the drawings, embodiments of the invention are schematically illustrated. In the drawing:

FIG. 1 is a schematic block diagram for illustrating the basic structure of the device used,

FIG. 2 shows as an example an illustration of a pattern of the body weight plotted over time,

FIG. 3 is a sequence diagram for illustrating the operation of the method according to the invention.

FIG. 1 schematically shows a person 1 who is connected in a lying state through measuring cables 2, 3 to a measuring device 4. The measuring device 4 is connected to a control device 5. Typically, the control device 5 makes an evaluation unit available.

For facilitating operating input, the control device 5 may be coupled to a keyboard 6. Alternatively, other input devices can also be used.

Moreover, the control device 5 is connected to a display 7 and a storage unit 8.

In accordance with a typical process sequence, the respective person is measured at a first point in time (T0) with the use of the device according to the invention. This value is stored in the device, preferably with an assignment of an unequivocal identification number of the respective patient. If an actual weight of the patient should be known from a point in time (TP) further back, this actual last known weight can be taken into consideration.

In accordance with a preferred manner of carrying out the method, serial measurements at points in time (TX) are measured against values of the point in time (T0). This reinforces carrying out a serial measurement as well as a serial illustration. This makes it possible for an aide of the patient to recognize whether the state of nutrition of the patient is changing. In particular, this can be done without knowing the actual exact value of the body weight.

For documenting the respective measurement results, it is possible to equip the device with a printer. In addition, it is possible to carry out continuous measurements. With respect to the technical construction, the device may be portable or stationary. 

1-4. (canceled)
 5. A method for determining body weight of a person, comprising the steps of: determining, with respect to measurement technology, at least one parameter typical for a biological impedance measurement; transmitting a measurement value to an evaluation unit; and processing the measurement value in the evaluation unit together with at least one additional individual data of the person and determining an estimated value for the body weight of the patient, taking into consideration statistical data concerning other persons.
 6. The method according to claim 5, wherein the evaluation unit additionally takes into consideration at least one past measurement with respect to time.
 7. The method according to claim 5, including carrying out a serial measurement.
 8. A device for determining body weight of a person, comprising: at least one sensor for determining at least one parameter typical for a biological impedance measurement; an evaluation unit coupled to the sensor, wherein the evaluation unit includes an individual storage unit for individual data of the person and a reference storage unit for statistical data concerning other persons, the evaluation unit being constructed for linking the at least one measurement parameter to contents of the individual storage unit as well as to contents of the reference storage unit. 